can cause gastrointestinal disturbances but since you are using it for past more than one year,this looks unlikely to be the cause.
Most likely the cause could be by eating a very acidic diet.
Meat,grains,junk foods,dairy products are acidic foods and can cause this problem.
Do's for you ....
Take more of fruits and green vegetables which are alkaline.
A healthy diet consists of 80% alkaline and 20 % acid foods.
Take plenty of water.
Do regular exercises.
Rebalance your intestinal bacterial flora by taking probiotic
supplements like lactobacillus acidophilus
and plenty of yoghurt.
Control your sugar levels meticulously.
I think it should solve your problem.